Oral Swab Specimens Research Articles

Molecular epidemiology and temporal dynamic of SARS-CoV-2 imported from Hong Kong to mainland China

Tracking the genome diversity and evolution of virus like severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was the hotspot of current researches, which were essential for the developing of prevention strategies and therapeutic vaccines. In the current study, a total of 206073 oral or nasopharyngeal swab specimens were collected in 2022 from entry populations originated from Hong Kong, among which 141 whole genome sequences were obtained through next-generation sequencing and analyzed. Two major Omicron sub-lineages were identified: BA.2.2 (70.21%, 99/141) and BA.5 (24.11% 34/141). An average of 53.22 mutations was emerged in the genome, with S protein and ORF1a harboring the highest number of mutations among structure proteins and non-structure proteins (p<0.001), respectively, making them the most variable regions. The temporal changes of the mutations among each protein were unique, indicating the distinct evolution pattern of these proteins. A novel mutation in the Nsp5 (3 C-like proteinase) was reported for the first time. As it may influence the viral replication and transcription, further monitoring is needed. The data reported here highlighted the importance of monitoring the SARS-CoV-2 genome and would be useful for the generation of evidence-based prevention programs and effective vaccines to COVID-19.

Performance Evaluation of the STANDARD i-Q COVID-19 Ag Test with Nasal and Oral Swab Specimens from Symptomatic Patients.

We evaluated the diagnostic performance of the STANDARD i-Q COVID-19 Ag Test, which was developed to detect viral antigens, using nasal and oral swabs. Sixty positive and 100 negative samples were analyzed. We determined the distribution of the Ct values according to the day of sample collection after symptom onset, the diagnostic performance of the total samples and subgroups separated by Ct value or time of sample collection, and the Ct value at which maximal accuracy was expected. No differences were observed in Ct values, except for the samples obtained on the day of symptom onset. The diagnostic sensitivity and specificity of the oral swabs were 75.0 and 100.0%, respectively, whereas those of the nasal swabs were 85.0 and 98.0%, respectively. The sensitivity was higher in samples with a high viral load collected earlier than those collected later, although the difference was not significant. False-negative results were confirmed in all samples with a Ct value ≥ 30.0. These results indicate that tests using oral and nasal swabs are helpful for diagnosing acute symptomatic cases with suspected high viral loads. Our tests exhibited relatively low sensitivity but high specificity rates, indicating the need to assess negative antigen test results.

Prevalence and risk factors of oral human papillomavirus infection among 4212 healthy adults in Hebei, China

BackgroundHuman papillomavirus (HPV) infection is an essential cause of oropharyngeal squamous cell carcinoma that is increasing in incidence worldwide. However, little is known about the epidemiology of oral HPV infection among healthy adults in China.MethodsA study in northern China was conducted in 2021 as baseline data of Diverse Life-Course Cohort (DLCC). Residents who aged above 20 were eligible to participate. Oral swab specimens and questionnaires were collected from 4226 participants. HPV DNA in oral exfoliated cells was tested by Nested Polymerase Chain Reaction approach and sequencing. Univariate and multivariate analyses were performed to assess the associations between exposure factors and oral HPV infection.ResultsOverall prevalence of oral HPV infection was 4.08% (95%CI, 3.69%-4.68%). The most prevalent HPV type detected was HPV-81 (1.35%; 95% CI, 1.00%–1.70%), followed by HPV-16 (0.64%; 95% CI, 0.40%–0.88%). Oral HPV infection presented a bimodal pattern with respect to age in male and female participants. Oral HPV prevalence of male participants was significantly higher than prevalence of female participants (5.0% versus 3.6%, P = 0.041). Prevalence of oral HPV was higher among current smokers (OR = 1.59; 95% CI, 1.11–2.29; P = 0.039) and current drinkers (OR = 1.60; 95% CI, 1.14–2.25; P = 0.023). Current alcohol consumption was independently associated with oral HPV infection (OR = 1.74; 95% CI, 1.22–2.50; P = 0.010).ConclusionsAmong healthy adults aged above 20 in Hebei, China, the prevalence of high-risk HPV infection was 1.92% (95%CI, 1.51%-2.34%). Oral HPV prevalence was independently associated with alcohol consumption. More tailored prevention strategies are needed to prevent oral HPV infection through smoking cessation, reduction of alcohol consumption, and HPV vaccination.

Candida Albicans CT Value in Asthmatics with Prolonged Corticosteroid Inhaler Uses

Corticosteroid inhaler is one of the first-line drugs given for the control and prevention of asthma attacks in the long term and continuously. The use of corticosteroid inhalers for a long time has systemic side effects in the oral cavity which can be a predisposing factor for normal fungal infection of Candida albicans microflora, an increase of Candida albicans’s amount in the oral cavity can cause oral candidiasis. Candida albicans detection using q-PCR to detect specific genes in oral swab specimens can provide an indirect picture of the amount of Candida albicans in the samples taken. The purpose of this study was to determine the relationship between the length of use of corticosteroid inhalers and the cycle threshold value in oral swab samples of asthma patient. This type of research is correlational research with data collection techniques using a purposive sampling technique on 30 respondents at the Lung Polyclinic at Bhayangkara Hospital H.S Samsoeri Mertojoso Surabaya who fit the inclusion criteria. Samples were examined using q-PCR to detect specific genes in the ITS-2 region to detect Candida albicans. This research was conducted at the Molecular Biology Laboratory of the Ministry of Health Surabaya Polytechnic during the period April – May 2023. The results showed that there were 26 samples (86.7%) positive for the ITS-2 gene and 4 samples (13.3%) negative for the ITS-2 gene. with sig. 0.307 so that it can be concluded that there is no relationship between the length of use of corticosteroid inhalers and the cycle threshold value of C. albicans in asthmatic’s oral swab sample.

Epidemiology of oral human papillomavirus infection among diverse Chinese adults in typical areas of China: Findings from the DLCC study.

Human papillomavirus (HPV) infection is a predominant cause of oropharyngeal squamous cell carcinoma. However, there is limited knowledge about the epidemiology of oral HPV infections among adults in China. We collected data from a prospective cohort that enrolled participants in mainland China. A total of 9867 participants aged at least 20 years provided oral swab specimens in typical areas of China (Hebei and Guangdong provinces) in 2021. HPV DNA in oral exfoliated cells was tested using Nested Polymerase Chain Reaction and sequencing. Prevalence among sub-populations was compared. Multivariable logistic regression models were employed to assess possible factors influencing oral HPV infection. The overall prevalence of oral HPV infection was 3.0% [95% confidence interval (CI):2.68%-3.36%]. Among those infected, 1.3% (1.08%-1.53%) were infected with high-risk HPV types. Men had a higher age-standardized HPV infection prevalence (3.6%, 2.96-4.29%) compared to their female counterparts (2.7%, 2.35-3.12%). People in Hebei had a higher age- and sex-standardized prevalence (4.1%, 3.50%-4.70%) than those in Guangdong (2.2%, 1.80%-2.56%). Generally, men (odds ratio [OR] and 95% CI: 1.42, 1.09-1.85) and people in Hebei (2.01, 1.53-2.65) had higher odds of any type of HPV infection. Additionally, people living in urban areas had a 2.15-fold (1.43-3.26) higher odds of high-risk HPV infection. This study reveals a low prevalence of oral HPV infection with significant geographic and sex differences among Chinese population. This is the first study to report the epidemiological characteristics of oral HPV infection among Chinese adults in diverse geographic areas with large sample size.

Quantification of domestic cat hepadnavirus DNA in various body fluid specimens of cats: the potential viral shedding routes.

Domestic cat hepadnavirus (DCH) belongs to the Hepadnaviridae family together with human hepatitis B virus (HBV) that remains to be a major health problem worldwide. The transmission of HBV infectious virion has been one of the essential factors that contribute to high number of HBV infection in humans. It has been long known that various body fluid specimens of human with chronic HBV infection contain HBV DNA and demonstrated to be infectious. In contrast to this knowledge, the detection of DCH in various body fluid specimens of cats, has not been reported. This study explored the detection of DCH DNA in various body fluid specimens of cats by quantitative polymerase chain reaction (qPCR) and investigated whether the detection of DCH DNA from broader routes was correlated with any genomic diversity by phylogenetic analysis. A total of 1,209 body fluid specimens were included, and DCH DNA was detected not only in 4.70% (25/532) of blood samples; but also in 12.5% (1/8), 1.14% (1/88), 2.54% (10/394), and 1.65% (3/182) of auricular swab (AS), nasal swab (NS), oral swab (OS), and rectal swab (RS) specimens, respectively. Furthermore, the level of DCH DNA detected in the blood was significantly correlated with DCH DNA detection in OS (P = 0.02) and RS (P = 0.04) specimens. Genomic analysis revealed that there was no notable genomic diversity within the complete genome sequences obtained in this study. In conclusion, this study highlighted the presence of DCH DNA in various body fluid specimens of cats, and the potential role of these specimens in DCH horizontal transmission within the cat population warrants further studies.

Detection of Rotavirus in Respiratory Specimens From Bangladeshi Children Aged

To examine the potential for respiratory transmission of rotavirus, we systematically assessed if rotavirus RNA is detectable by real-time quantitative reverse transcription-polymerase chain reaction from nasal and oropharyngeal swab specimens of Bangladeshi children with acute rotavirus gastroenteritis. Forehead swabs were collected to assess skin contamination. Among 399 children aged <2 years hospitalized for gastroenteritis during peak rotavirus season, rotavirus RNA was detected in stool, oral, nasal and forehead swab specimens of 354 (89%). A subset was genotyped; genotype was concordant within a child's specimen set and several different genotypes were detected across children. These findings support possible respiratory transmission of rotavirus and warrant further investigation.

Tick salivary gland components dampen Kasokero virus infection and shedding in its vertebrate reservoir, the Egyptian rousette bat (Rousettus aegyptiacus)

BackgroundThe human-pathogenic Kasokero virus (KASV) circulates in an enzootic transmission cycle between Egyptian rousette bats (ERBs; Rousettus aegyptiacus) and their argasid tick ectoparasites, Ornithodoros (Reticulinasus) faini. Although tick salivary gland components have been shown to potentiate virus infection in vertebrate non-reservoirs (i.e. incidental hosts or small animal models of disease), there is a lack of information on the effect of tick salivary gland components on viral infection and shedding in vertebrate reservoirs.MethodsTo determine the impact of tick salivary gland components on KASV infection and shedding in ERBs, KASV loads were quantified in blood, oral swab, rectal swab, and urine specimens collected daily through 18 days post inoculation from groups of ERBs intradermally inoculated with KASV or KASV + O. (R.) faini tick salivary gland extract (SGE).ResultsBats inoculated with KASV + tick SGE had significantly lower peak and cumulative KASV viremias and rectal shedding loads compared to bats inoculated with KASV only.ConclusionsWe report for the first time to our knowledge that tick salivary gland components dampen arbovirus infection and shedding in a vertebrate reservoir. This study advances our understanding of biological factors underlying arbovirus maintenance in nature.Graphical abstract

Detection of Virulence Factors from Candida spp. Isolated from Oral and Vaginal Candidiasis in Iraqi Patients.

Yeast-like fungi (YLF) of the genus Candida are unicellular microorganisms of relatively large size and rounded shape, aerobes, and belong to conditionally pathogenic microorganisms. The genus Candida includes approximately 150 species, which are classified as Deuteromycetes due to the absence of a sexual stage of development. This study aimed to identify virulence factors from Candida spp. isolated from oral and vaginal candidiasis. Fifty-eight oral and vaginal swab specimens were collected from patients, including (28) oral swabs from children and (30) vaginal swabs from different infected women. All isolates were subjected to direct examination, Morphological tests, Germ tube formation, growth at 45ºC, CHROM agar Candida culture, and VITEK 2 Compact system to ensure this diagnosis. (31) isolates were identified as Candida spp., including (21) (C. albicans (14), C. glabrata (1), C. guilliermondii (2), C. dubliniensis (3), C. parapsilosis (1)) were isolated from oral swabs and (10) isolates includedC. parapsilosis (4), C. albicans (6) were isolated from vaginal swabs. Moreover, these isolates had been detected to have some virulence factors, including phospholipase, esterase, proteinase, coagulase, hemolysin, and biofilm formation. Different species of Candida were isolated and identified from oral and vaginal. Phospholipase (Pz), Esterase (Ez), and Proteinase (Prz) were produced by 19 (61.29%), 16 (51.61%), and 26(83.87%), respectively, out of 31 isolates, whereas. All isolates produce coagulase enzyme except C. dubliniensis, which did not produce coagulase enzyme. All Candida spp. isolates produce hemolysin and biofilm formation in different percentages.

Oral Swab Specimens Tested With Xpert MTB/RIF Ultra Assay for Diagnosis of Pulmonary Tuberculosis in Children: A Diagnostic Accuracy Study.

Microbiologic diagnosis of childhood tuberculosis may be difficult. Oral swab specimens are a potential noninvasive alternative to sputum specimens for diagnosis. This was a prospective diagnostic accuracy study of oral swab specimens (buccal and tongue) for pulmonary tuberculosis diagnosis in children (aged ≤ 15 years) in 2 South African hospital sites. Children with cough of any duration as well as a positive tuberculin skin test result, tuberculosis contact, loss of weight, or chest radiograph suggestive of pulmonary tuberculosis were enrolled. Two induced sputum specimens were tested with Xpert MTB/RIF (or Xpert MTB/RIF Ultra) assay and liquid culture. Oral swab specimens were obtained before sputum specimens, frozen, and later tested with Xpert MTB/RIF Ultra. Children were classified as microbiologically confirmed tuberculosis, unconfirmed tuberculosis (receipt of tuberculosis treatment), or unlikely tuberculosis according to National Institutes of Health consensus definitions based on sputum microbiologic results. Among 291 participants (median age [interquartile range], 32 [14-73] months), 57 (20%) had human immunodeficiency virus (HIV), and 87 (30%) were malnourished; 90 (31%) had confirmed pulmonary tuberculosis (rifampicin resistant in 6 [7%] ), 157 (54%), unconfirmed pulmonary tuberculosis, and 44 (15%), unlikely tuberculosis. A single oral swab specimen was obtained from 126 (43%) of the participants (tongue in 96 and buccal in 30) and 2 swab specimens from 165 (57%) (tongue in 110 and buccal in 55). Sensitivity was low (22% [95% confidence interval, 15%-32%]) for all swab specimens combined (with confirmed pulmonary tuberculosis as reference), but specificity was high (100% [91%-100%]). The highest sensitivity was 33% (95% confidence interval, 15%-58%) among participants with HIV. The overall yield was 6.9% with 1 oral swab specimen and 7.2% with 2. Use of the Xpert MTB/RIF Ultra assay with oral swab specimens provides poor yield for microbiologic pulmonary tuberculosis confirmation in children.

Oral microbiome of electronic cigarette users: A cross-sectional exploration.

Electronic cigarettes have increased in popularity globally. Vaping may be associated with oral symptoms and pathologies including dental and periodontal damage, both of which have an underlying microbial etiology. The primary aim of this pilot study, therefore, was to compare the oral microbiome of vapers and non-vapers. This secondary data analysis had a cross-sectional comparative descriptive design and included data for 36 adults. Bacterial 16S rRNA genes were extracted and amplified from soft tissue oral swab specimens and taxonomically classified using the Human Oral Microbiome Database. Data for 18 vapers and 18 non-vapers were included in this study. Almost 56% of the vapers also smoked conventional cigarettes. Beta diversity differences were identified between vapers and non-vapers. Vapers had a significantly higher relative abundance of an unclassified species of Veillonella compared with non-vapers. Dual users had higher alpha diversity compared with exclusive vapers. Beta diversity was also associated with dual use. Multiple OTUs were identified to be associated with dual use of e-cigarettes and conventional cigarettes. Vapers exhibit an altered oral microbiome. Dual use of electronic cigarettes and conventional cigarettes is associated with the presence of several known pathogenic microbes.

Robust Saliva-Based RNA Extraction-Free One-Step Nucleic Acid Amplification Test for Mass SARS-CoV-2 Monitoring.

Early diagnosis with rapid detection of the virus plays a key role in preventing the spread of infection and in treating patients effectively. In order to address the need for a straightforward detection of SARS-CoV-2 infection and assessment of viral spread, we developed rapid, sensitive, extraction-free one-step reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and reverse transcription loop-mediated isothermal amplification (RT-LAMP) tests for detecting SARS-CoV-2 in saliva. We analyzed over 700 matched pairs of saliva and nasopharyngeal swab (NSB) specimens from asymptomatic and symptomatic individuals. Saliva, as either an oral cavity swab or passive drool, was collected in an RNA stabilization buffer. The stabilized saliva specimens were heat-treated and directly analyzed without RNA extraction. The diagnostic sensitivity of saliva-based RT-qPCR was at least 95% in individuals with subclinical infection and outperformed RT-LAMP, which had at least 70% sensitivity when compared to NSBs analyzed with a clinical RT-qPCR test. The diagnostic sensitivity for passive drool saliva was higher than that of oral cavity swab specimens (95% and 87%, respectively). A rapid, sensitive one-step extraction-free RT-qPCR test for detecting SARS-CoV-2 in passive drool saliva is operationally simple and can be easily implemented using existing testing sites, thus allowing high-throughput, rapid, and repeated testing of large populations. Furthermore, saliva testing is adequate to detect individuals in an asymptomatic screening program and can help improve voluntary screening compliance for those individuals averse to various forms of nasal collections.

Self-collected unstimulated saliva, oral swab, and nasopharyngeal swab specimens in the detection of SARS-CoV-2.

ObjectivesThe presence of SARS-CoV-2 virus in the saliva of patients infected with COVID-19 has been confirmed by several studies. However, the use of saliva for the diagnosis of COVID-19 remains limited, because of the discrepancies in the results, which might be due to using different saliva sampling methods. The purpose of this study was to compare the consistency of SARS-CoV-2 detection using two different saliva sampling methods (oral swab and unstimulated saliva) to that of the standard nasopharyngeal swab.MethodsFifty-five subjects were recruited from a pool of COVID-19 inpatient at the Hospital Israelita Albert Einstein (HIAE), Brazil. Nasopharyngeal swab, oral swab, and self-collected unstimulated saliva samples were examined for SARS-CoV-2 using RT-PCR.ResultsSelf-collected unstimulated saliva demonstrated 87.3% agreement in the detection of SARS-CoV-2 virus as compared with the nasopharyngeal swab, while oral swab displayed 65.9% agreement when compared to nasopharyngeal swab and 73% when compared to self-collected unstimulated saliva.ConclusionUnstimulated self-collected saliva samples have shown a higher agreement with the nasopharyngeal swab samples for SARS-COV-2 detection than that obtained when using oral swab samples.Clinical relevanceThis study compares the accuracy of COVID-19 test using different saliva sampling methods to that of nasopharyngeal swab. Given the need for a simple self-applied test that can be performed at home, our findings support the efficacy of self-collected unstimulated saliva samples in the diagnosis of SARS-CoV-2 infection, alleviating the demands for swab supplies, personal protective equipment, and healthcare personnel.

Efficacy of Rose Bengal and Curcumin mediated photodynamic therapy for the treatment of denture stomatitis in patients with habitual cigarette smoking: A randomized controlled clinical trial

BackgroundCigarette smoking in conjugation with bad oral hygiene is considered a typical predisposing factor for many oral diseases including denture stomatitis. This study investigated the effect of Rose Bengal (RB)-and Curcumin (CUR)-mediated photodynamic therapy (PDT) in comparison with nystatin therapy in the intervention of denture stomatitis in cigarette smokers. MethodsOverall, 45 habitual cigarette smokers aged ~58 years having denture stomatitis were categorized into three groups: Group-I – RB-mediated PDT, Group-II – CUR-mediated PDT, and Group-III – Nystatin therapy. The primary outcome of the interest was: counts of Candida colony from denture surface and palatal mucosa, calculated as CFU/mL, whereas the prevalence of Candida species determined in 3 research groups comprised the secondary outcome. Oral swab specimens were gathered from the denture surfaces and palatal mucosa. All clinical assessments were performed at baseline, 6 weeks, and 12 weeks. ResultsC. albicans was the most prevalent yeast identified on both denture surfaces and palatal mucosa, followed by C. tropicalis and C. glabrata. A considerable decrease in the CFU/mL scores were observed in Group-I and Group-II at the end of the interventions and on the 12-week follow-up (p<0.05). Group-I, II, and III demonstrated clinical efficacy rates of 53%, 51%, and 49%, respectively. ConclusionCUR-and RB-mediated PDT was found to be as effective as topical Nystatin therapy for the intervention of denture stomatitis among cigarette smokers.

Diagnostic Yield of Oral Swab Testing by TB-LAMP for Diagnosis of Pulmonary Tuberculosis.

ObjectiveA prospective study was conducted to ascertain the accuracy of oral swab specimens collected in the early morning, spot and at night for detecting pulmonary tuberculosis (TB).MethodsWe prospectively enrolled patients with symptoms suggestive of pulmonary TB in Beijing Chest Hospital. An early morning sputum specimen was collected from each patient for GeneXpert MTB/RIF (Xpert) and mycobacterial culture. In addition, three oral swabs were collected for TB-LAMP testing.ResultsWith the combined results of three oral swab specimens, the proportion of Mycobacterium tuberculosis (MTB)-positive cases achieved 40.6%, which was comparable to results for Xpert and MGIT (P=0.603). Using Xpert plus MGIT as reference, the sensitivity of OS-LAMP on a single specimen ranged from 32.6% on the night oral swab to 50.0% on the morning swab. The combination of three oral swab specimens correctly identified 38 MTB-positive cases, indicating an overall sensitivity of 82.6%, which was significantly higher than that of a single oral swab specimen (P<0.001, P=0.001).ConclusionOral swab can be used as an alternative specimen for diagnosis of pulmonary TB using TB-LAMP. Morning oral swab exhibits the highest sensitivity, and the inclusion of more specimens at different time points provides compensation in diagnostic sensitivity with single oral swab.

Self-Collected Oral Fluid and Nasal Swabs Demonstrate Comparable Sensitivity to Clinician Collected Nasopharyngeal Swabs for Coronavirus Disease 2019 Detection.

We compared self-collected oral fluid swab specimens with and without clinician supervision, clinician-supervised self-collected mid-turbinate (nasal) swab specimens, and clinician-collected nasopharyngeal swab specimens for the detection of SARS-CoV-2. Supervised oral fluid and nasal swab specimens performed similarly to clinician-collected nasopharyngeal swab specimens. No sample type could detect SARS-CoV-2 infections amongst all positive participants.

Evaluation of DNA methylation in matched oral swab and tissue specimens from Chinese patients with oral squamous cell carcinoma

The DNA methylation statuses of the paired box 1 (PAX1) and zinc finger protein 582 (ZNF582) genes have shown promise in the detection of oral squamous cell carcinoma (OSCC). The aim of this study was to investigate the ability of PAX1 and ZNF582 methylation to distinguish OSCC and the adjacent normal tissue among cancer patients. This study included 67 patients with OSCC. The methylation levels of these two genes were analysed in tissue specimens (lesion site and adjacent normal site) and in oral swabs (lesion site and contralateral normal site). Levels of DNA methylation were higher at lesion sites than at the corresponding normal sites. According to receiver operating characteristics curve analysis, the area under the curve for PAX1 and ZNF582 methylation ranged from 0.73 to 0.82. No significant difference was observed between tissue specimens and oral swabs (PAX1, P= 0.41; ZNF582, P=0.28). For the oral swab, PAX1 methylation was more pronounced in bone invasion (Z=1.988, P= 0.047), and ZNF582 methylation was more pronounced in early-stage (Z=2.354, P= 0.02) and well-differentiated tumours (Z=3.731, P= 0.0002). Hypermethylated PAX1 and ZNF582 are effective biomarkers to distinguish lesion sites and corresponding normal sites in tissue specimens and oral swabs from OSCC patients.

Ebola Patient Virus Cycle Threshold and Risk of Household Transmission of Ebola Virus.

Identifying risk factors for household transmission of Ebola virus (EBOV) is important to guide preventive measures during Ebola outbreaks. We enrolled all confirmed persons with EBOV disease who were the first case patient in a household from December 2014 to April 2015 in Freetown, Sierra Leone, and their household contacts. Index patients and contacts were interviewed, and contacts were followed up for 21 days to identify secondary cases. Epidemiologic data were linked to EBOV real-time reverse-transcription polymerase chain reaction cycle threshold (Ct) data from initial diagnostic specimens obtained from enrolled index case patients. Ct data were available for 106 (71%) of 150 enrolled index patients. Of the Ct results, 85 (80%) were from blood specimens from live patients and 21 (20%) from oral swab specimens from deceased patients. The median Ct values for blood and swab specimens were 21.0 and 24.0, respectively (P = .007). In multivariable analysis, a Ct value from blood specimens in the lowest quintile was an independent predictor of both increased risk of household transmission (P = .009) and higher secondary attack rate among household contacts (P = .03), after adjustment for epidemiologic factors. Our findings suggest the potential to use Ct values from acute EBOV diagnostic specimens for index patients as an early predictor of high-risk households and high-risk groups of contacts to help prioritize EBOV disease investigation and control efforts.

Identification and molecular characterization of Porphyromonas gulae fimA types among cat isolates

Porphyromonas gulae, a Gram-negative black-pigmented anaerobe, is one of several major periodontal pathogens of animals. P. gulae isolates from dogs have been classified into three genotypes based on a 41-kDa filamentous appendage (FimA) on the cell surface, which is closely related to virulence in periodontal disease. However, other specific bacterial virulence factors contributing to the aggravation of periodontal disease in cats remain elusive. In the present study, we assessed FimA diversity in P. gulae isolates from cats and examined whether this diversity influenced periodontal condition. The putative amino acid sequences of FimA from 15 P. gulae isolates from 13 cats were classified into three genotypes (types A, B, and C), which showed 95–100% identity and similarity to the fimA types in dogs. The type C isolate showed greater adhesion and invasion properties in periodontal ligament fibroblasts as well as stronger inhibition of scratch closure of the cells compared with type A and B isolates. Next, a PCR-based method for identification of fimA genotype was developed and used to analyze 99 oral swab specimens from cats. High fimA type A detection rates were observed regardless of the periodontal condition, whereas types B and C were frequently detected from subjects with moderate and severe periodontitis, respectively. These results suggest that P. gulae isolates from cats can be classified into three types based on fimA genotype, which may be closely related to virulence in periodontitis.

A fatal case associated with respiratory syncytial virus infection in a young child

BackgroundRespiratory syncytial virus (RSV) is the most common viral cause of pediatric bronchiolitis and pneumonia worldwide. Risk factors for high mortality and prolonged morbidity after RSV infection include premature birth, bronchopulmonary dysplasia, congenital heart disease, and Down syndrome. However, some previously healthy, full-term children who are infected with RSV also require hospitalization and even experience severe sequelae or death.Case presentationIn this report, we present the case of an RSV-associated death of a child who was born at full-term and developed normally up to the age of 2 years old. Cardiopulmonary arrest occurred within 3 days after the onset of symptoms, which included cough and high fever. Complete brain edema was prominent, and encephalopathy was developing. Viral antigen detection and microbiome analyses of oral swab and nasopharyngeal aspirate specimens verified an RSV infection, while bacterial culture of blood specimens yielded negative results. The RSV strain detected in this patient was subtyped as RSVB9, and no mutation was found in the six antigenic sites for targeted drugs or vaccines.ConclusionsThe patient had a severe infection associated with RSV, which was very likely the cause of her central nervous system infection and acute neurological complications.